Project Summary/Abstract Almost 25% of intensive care unit (ICU) survivors experience post-ICU cognitive impairment comparable to that of mild Alzheimer?s disease; about 33% suffer from cognitive impairment equivalent to moderate traumatic brain injury. Critically ill older adults (ages 65 and older) have the highest incidence of mechanical ventilation and are at most risk for post-ICU cognitive impairment. Mechanically ventilated ICU patients experience worse sleep than those who are not ventilated. The proposed research focuses on older adult ICU survivors who required mechanical ventilation for survival. The scientific premises are: 1) sleep deficiency may be associated with post-ICU syndrome and cognitive impairment, and 2) sleep may be a modifiable risk factor to prevent post-ICU cognitive impairment. Understanding sleep deficiency is essential to design personalized symptom management interventions to prevent post-ICU cognitive decline. This is the first study to evaluate the longitudinal effect of sleep deficiency on post-ICU cognitive impairment among older adult ICU survivors. Specific Aim 1 is to determine the daytime and nighttime sleep quality (sleep architecture and sleep environment) of older adult ICU survivors who required mechanical ventilation while in ICU. Sleep (i.e., polysomnography and actigraphy) will be measured at time of transfer out of ICU, and again at 1 and 3 months post-hospital discharge. Polysomnography will describe sleep architecture (sleep duration, efficiency, fragmentation, and latency; N1, N2, N3, and REM stages; and cortical and sympathetic arousals). Actigraphy will describe sleep environment (ambient light/dark levels and motion/inactivity). Specific Aim 2 is to determine the effect size of the longitudinal relationship between sleep deficiency and post-ICU cognitive impairment. Cognitive function (i.e., executive function and working memory) will be assessed at time of transfer out of ICU, and again at 1 and 3 months post-hospital discharge, using selected measures from the NIH Toolbox Cognition Battery. Additional related data (biological variables including age, sex, race/ethnicity, and clinical history such as obstructive sleep apnea) will be collected to explore risk factors for sleep deficiency and post- ICU cognitive impairment. Data will provide direction on development of nursing interventions (e.g., promoting sleep consolidation, restructuring sleep environment, reestablishing circadian rhythm, decreasing daytime sleepiness) to best target and prevent post-ICU cognitive impairment. The proposed research will take place in one of the largest ?minority-majority? metropolitan areas in the United States?65% of Miami?s population is Hispanic/Latino. The proposed project will support the applicant in her career goal to develop her professional identity as a nurse scientist, with an individualized, rigorous training program of symptom science research and longitudinal data analysis centered on geriatrics, sleep, cognitive neuropsychology, and critical care. The proposed training plan integrates the scientific and analytic expertise of an interdisciplinary mentorship team.